title: Reevesioside F induces potent and efficient anti-proliferative and apoptotic activities through Na⁺/K⁺-ATPase α3 subunit-involved mitochondrial stress and amplification of caspase cascades.
abstract: Reevesioside F, isolated from Reevesia formosana, induced anti-proliferative activity that was highly correlated with the expression of Na⁺/K⁺-ATPase α₃ subunit in several cell lines, including human leukemia HL-60 and Jurkat cells, and some other cell lines. Knockdown of α₃ subunit significantly inhibited cell apoptosis suggesting a crucial role of the α₃ subunit. Reevesioside F induced a rapid down-regulation of survivin protein, followed by release of cytochrome c from mitochondria and loss of mitochondrial membrane potential (ΔΨm). Further examination demonstrated the mitochondrial damage in leukemic cells through Mcl-1 down-regulation, Noxa up-regulation and an increase of the formation of truncated Bid, tBim and a 23-kDa cleaved Bcl-2 fragment. Furthermore, reevesioside F induced an increase of mitochondria-associated acetyl α-tubulin that may also contribute to apoptosis. The caspase cascade was profoundly activated by reevesioside F. Notably, the specific caspase-3 inhibitor z-DEVD-fmk significantly blunted reevesioside F-induced loss of ΔΨm and apoptosis, suggesting that caspase-3 activation may further amplify mitochondrial damage and apoptotic signaling cascade. In spite of being a cardiac glycoside, reevesioside F did not increase the intracellular Ca²⁺ levels. Moreover, CGP-37157 which blocked Na⁺/Ca²⁺ exchanger on plasma membrane and mitochondria did not modify reevesioside F-mediated effect. In summary, the data suggest that reevesioside F induces apoptosis through the down-regulation of survivin and Mcl-1, and the formation of pro-apoptotic fragments from Bcl-2 family members. The loss of ΔΨm and mitochondrial damage are responsible for the activation of caspases. Moreover, the amplification of caspase-3-mediated signaling pathway contributes largely to the execution of apoptosis in leukemic cells.
authors.affiliation: School of Pharmacy, National Taiwan University, No.1, Sect. 1, Jen-Ai Rd, Taipei 100, Taiwan.
authors.forename: She-Hung
authors.initials: SH
authors.lastname: Chan
authors.forename: Wohn-Jenn
authors.initials: WJ
authors.lastname: Leu
authors.forename: Lih-Ching
authors.initials: LC
authors.lastname: Hsu
authors.forename: Hsun-Shuo
authors.initials: HS
authors.lastname: Chang
authors.forename: Tsong-Long
authors.initials: TL
authors.lastname: Hwang
authors.forename: Ih-Sheng
authors.initials: IS
authors.lastname: Chen
authors.forename: Ching-Shih
authors.initials: CS
authors.lastname: Chen
authors.forename: Jih-Hwa
authors.initials: JH
authors.lastname: Guh
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D053148:Caspase 3 / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins / Q000037:antagonists & inhibitors; D019660:Malvaceae / Q000737:chemistry; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D008928:Mitochondria / Q000187:drug effects*; D064549:Myeloid Cell Leukemia Sequence 1 Protein / Q000037:antagonists & inhibitors; D018384:Oxidative Stress / Q000187:drug effects*; D012503:Saponins / Q000302:isolation & purification / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D000077022:Survivin
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D053148:Caspase 3; D051034:Inhibitor of Apoptosis Proteins; D064549:Myeloid Cell Leukemia Sequence 1 Protein; D012503:Saponins; D000254:Sodium-Potassium-Exchanging ATPase; D000077022:Survivin; C107489:BIRC5 protein, human; C579095:MCL1 protein, human; C585486:reevesioside F; C488756:ATP1A3 protein, human
keywords: Bcl-2 family of protein; Mitochondrial damage; Na(+)/K(+)-ATPase α(3) subunit; Reevesioside F; Survivin